Malicious PDF — malware analysis report

Static analysis result for SHA-256 683869acccf992fd…

MALICIOUS

PDF

83.2 KB Created: 2021-06-13 09:12:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: b5da510e2f8a12b90d5f7d30986f3c30 SHA-1: 24c734e7d270ca0ada10df47ad927df588cc4a49 SHA-256: 683869acccf992fd4dc4416b3c7a33c7c0d32dcc4667dc402efc36e048b29954
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs, many hosted on compromised WordPress sites, suggesting it functions as a link farm to distribute further malicious content. The presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://allytemp.ru/uplcv?utm_term=english+11th+guide+pdf+download PDF link annotation
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608a2114f3ee1---16177126256.pdfIn PDF document text
    • http://coffee33.ru/archive/file/89789691769.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609efdcf76a51---3844382858.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/db8bbf0qcrh4ir00hjc0sj0ghu/31564656457.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/df37eaa09c7d01bb8d50e2fe73e87ad1/jabozamukexidebofewuloru.pdfIn PDF document text
    • https://kingyao.com/uploadfiles/files/20210612_212004_9060.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16073d9f4c035d---novarafawezatagezemaxu.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/2eaa2f7d400a201afb352cbc1b1ab46d/foxuzegepu.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/d4e8d40cc2b7cf10df330c8341f4b077/vanitodojimodabam.pdfIn PDF document text
    • https://adsbudget.net/userfiles/file/67636692283.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/gihe2s8vmku5inulv30kgarplu/vobadinugavobe.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/sh7j75gf6ashlisn5bekur4g5u/jetebezibe.pdfIn PDF document text
    • http://3will.org/soubory/files/fonuwunez.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076523dd04c8---vovoxolufudajegus.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC33 5308 bytes
SHA-256: 101ccaebcb8226ce914763f776615e6ab05b942b58ed4def9bafe1aa0c5176ac
font_01_sfnt_off0000fe61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE61 12060 bytes
SHA-256: 0f190552a9162b5b84c16aeb7116726703b242c2fad9a1b93662abcfc824051e
font_02_sfnt_off00011d61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D61 10040 bytes
SHA-256: f92794ef58798af32f2f4b111354d69964125d7cc96e4f1de0bb681df55d2562